<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id='app'>
        <ul>
            <li v-for="(item,index) in list" :key="index" >
                {{item}}
                <button @click="del(index)">删除</button>
            </li>
        </ul>
        <button @click="random">生成</button>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
        const app = new Vue({
        el: '#app',
        data: {
            id:1,
            list:[1]
        },
        methods:{
            random(){
                let random= Math.floor(Math.random() * 21)
                this.list.push(random) 
            },
            del(id){
                this.list.splice(id,1)
            }
        }
    })
    </script>
</body>
</html>